Printed circuit boards are typically populated with many surface-mounted circuit devices. Many small holes are formed in the boards to interconnect the layers of the circuit board. Of course, printed circuit board populated with other types of devices also need holes formed in the boards.
Drilling machines are typically used to drill the holes in the printed circuit boards. One exemplary type of system is described in U.S. Pat. No. 4,761,876, the entire contents of which are incorporated herein by this reference.
There has been a dramatic increase in the hole count on printed circuit boards, which makes the cost of drilling the holes a significant part of the total production cost. In addition, hole sizes are getting smaller. Small drills are more expensive and can not be fed with the same velocity as larger drills. Due to this fact, drilling time and cost are further increased.
It is known the multiple spindles can be employed in a drilling system, wherein the spindles are manually positioned in relation to each other. Manual positioning has the drawback of requiring significant setup time, to properly position the spindles. Moreover, each time the spindles are required to drill a new part or image, the spindles must be manually repositioned. This requires a very significant setup time as well.
Methods of producing holes by laser are known. However, laser technology does not offer a solution for producing large holes and holes through multilayer boards.
It would therefore be an advance in the art to provide a high throughput drilling system with increased throughput capacity, and which is capable of forming small as well as larger holes.
It would further be an advance in the art to provide a machine capable of mechanically forming larger as well as smaller holes with high throughput.